There is interesting research on the benefits of a specific form of glucosamine, N-acetyl-glucosamine, for MS patients [1,2].
N-acetyl-glucosamine is one of 8 essential sugars the human body needs. Glucosamine is it’s metabolic byproduct of, it is part of the glyconutrients family, known as a natural remedy for joint pain. For an excellent, though fairly enthusiatic, discussion on the possible benefits of N-acetyl-glucosamine, you can go to GlucoNutrients4Me , a non-medical site of health bloggers.
The new aspect of this research is the action of N-acetyl-glucosamine on the immune system. The possible benefits in keeping MS at bay should not come entirely as a surprise, considering another study showing the “regulation of immune cells, particularly in the activation processes of T and B lymphocytes..” 
Before you rush to N-acetyl-glucosamine sugar supplements, you have to understand that the research  was done on mice, and the disease studied was a model of MS (Experimental Autoimmune Encephalomyelitis ,or EAE), and not MS itself. Close enough, though, to be very exciting. Imagine a treatment bypassing the side effects of the current disease modifying drugs, interferons, immunosuppressants, etc.
Note that the studies  also suggests possible therapeutic value for this sugar as an immunomodulator and anti-tumor agent against neurodegeneration and cancer.
Some natural healing enthusiasts  have claimed that “There is no known adverse side effect to the intake of N-acetylglucosamine supplement…”, and even suggest a dosage “… although experts suggest that the intake of one gram daily for adults would be sufficient…”
The dietary sources for this sugar include:
- Bovine cartilage
- Shark cartilage (not ideal for diabetics and those with kidney disease)
- and Shiitake mushrooms (good news for people on vegetarians and kosher diets)
I will send you to WebMD  for the cautions on starting to take N-acetyl-glucosamine. Note the possible interference with other meds. The discussion on N-acetyl-glucosamine and diabetes is important: it might be ok for diabetics to take this sugar. Quoting WebMD: “…Therefore, glucosamine probably does not interfere with diabetes medications. To be cautious, if you take N-acetyl glucosamine and have diabetes, monitor your blood sugar closely…”
As always, talk to your Doctor..
 nutraingredients ; “glucosamine-like supplement may suppress MS:study”,Nathan Gray; oct 3rd,2011
 Journal of Biological Chemistry; “N-ACETYLGLUCOSAMINE INHIBITS T-HELPER 1 (TH1) / T-HELPER 17 (TH17) RESPONSES AND TREATS EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS”; Michael Demetriou et. al. , U. of california, Irvine,San Diego
 EMBO ; “The O-linked N-acetylglucosamine modification in cellular signalling and the immune system”